Mar 16, 2014 9:41 PM

I found this today while digging over my allotment in Kent. It appears to have a crystaline structure and weighs 11 grams. The "core" underneath appears to be orange like rust but it is not metallic. The surface is reflective and dark grey like haematite. Can anyone help please? Thanks John.

Thank you for your prompt reply (and photo compliment, only just got the camera last week so all a bit new to me but pleased with the results so far).

Wanting to know more about Marcasite I googled it and came up with this description from an unexpected place.... Ebay!! My lady is very "in to" Jewellery so will find the history part of interest too. I will include it for you below on the off chance you or, yours glean some interesting info from it as well.

Marcasite Silver Art Deco Jewellery Jewelry

A bit about Marcasite and Marcasite Jewellery. I'll endeavor to give a few clues on how to differentiate between old and new Marcasite Jewellery.

Marcasite is iron disulphide (FeS2) which has 2 distinct ways of forming crystals in nature. Pyrite (Fool's Gold) and Marcasite. The irony is that true Marcasite forms brittle, crumbling and unstable crystals and the jewellery we all know as "MARCASITE" is made from Pyrites, which is hard and stable. Someone must have been confused in the old days.

It has been used in many cultures for decoration over the years. Incas, Ancient Greeks and more.

It started to gain use and popularity in England during the 18th century and was frequently seen in lockets, brooches, and cameos, and as a substitute for "cut steel" beads that were popular as a jewellery adornment in Georgian times.

It really gained popularity after the death of Queen Victoria's husband. "Dark and Sombre" was in. Silver and Marcasite jewellery became the fashion for the middle class and continued to the end of the Art Deco Period. Although there is no large revival now, it has always maintained some popularity since then.

There are some really amazing pieces of jewellery made from Sterling Silver and Marcasite. In times when craftsmanship was less valuable a lot of skill was put into some pieces.

Most Marcasite is faceted as a flat bottomed many sided pyramid, similar to a Dutch Rose Cut. It has a stable dark metallic lustre with many shiny mirror-like facets.

If you are looking for genuine old pieces, here are a few things to consider.

Always make sure that it is Hallmarked with some sort of silver stamp.

Germany was a large producer of Marcasite jewellery before the Second World War for export and many pieces are stamped GERMANY

Is the body of the piece made by hand or cast? It is reasonably easy to tell on close examination. Hand made means lots of time spent making the item and usually older and of higher quality. That is not to say there are no quality cast old pieces, in fact the majority were cast.

The BEST clue is the way the Marcasite is set. When labour was cheaper (the old days), all quality Marcasites were mounted by "bead setting". The jeweller used a graver tool to curl a bit of base metal over the edge of the stone in a few places to secure it. That would have taken quite a bit of time as some pieces have 100's of stones in them. Modern pieces have the stones glued in so, with a magnifier, have a look at how the stone is held in place.

There are older pieces that have glued in stones but they are usually of inferior quality and fairly recognisable.

It is important to realise that good old pieces are now copied. The marcasites have to be removed to make a mould. So if you see a piece that has beads, supposedly holding the stones, examine it carefully and if it is a copy the beads will NOT be holding the stones, they just look like it and the stones are actually glued in. Missing stones. There are not many old pieces that haven't a missing stone or two. I don't let it worry me too much. Firstly, it is usually difficult to see the missing ones amongst all those others. In fact, many a time I have checked a piece quite thoroughly, only later to find that I missed a missing Marcasite. Secondly if you collect a bit of Marcasite jewellery, you will have some scrap pieces. They become a wonderful supply of replacement stones.

Old Silver Marcasite jewellery is a wonderful area for the collector. The are many high quality and very interesting pieces around and yet I don't think the price anywhere near reflects their beauty and workmanship. Keep an eye out!

LASTLY, I point out that I am not a jeweller and that the above guide is just that, a guide. I am a pawnbroker with 25 years experience. If you want professional advice go to a jeweller.

Bear in mind there are variants, such as arsenopyrite (more silvery) and chalcopyrite (more golden). Also Google bornite for some stunning metallic blues-purples. I'm not sure about the use of those in jewellery; I guess I'd steer clear of arsenopyrite - with the arsenic connection.

In general, as a matter of good practice, it would be preferable if you posted links to related info rather than copy and pasting it. I know it is easier to read if pasted, but there are issues of infringements of rights and general courtesy. When posting a link to an image, also include a link to the page where you found it. That makes it easier for people to follow-up, and maybe to see a caption or other text orphaned from the image on its own.

I hope you find other buried treasure on your allotment, or elsewhere.